Tube straightening and bending tool



API'l 3, 1955 c. E. MARTIN, sR 2,740,309

TUBE STRAIGHTENING AND BENDING TOOL Filed May 4, 1953 TUBE STRAIGHT ENING 'AND' BENDING TOOL Cecil E. Martin, Sr.,.Petersburg, Va. Application May 4, 1953, Serial No.v 352,932

s claims. (ci. r11- 15)Y This inventionrelates to a combined tube straightening and bending tool.

In the use of metal tubingof the sort whichis employed in uid connections, and more particularly in refrigeration lines and fuel and oil lines in automobiles and aircraft, it is often necessary to straighten a bend lin a piece of tubing preparatory to changing the connections, and the tubing must thereafter be bent to a new desired shape. Furthermore, certain types of such tubing are quitesoft and become accidentally bent duringinstallation and must be straightened to make a clean'connection;

In order to manipulate metal tubing in any desired manner, it is necessary toemployboth tube straightening tools and tube bending tools.

The principal object of the presentinvention, therefore, is to provide a simple, compacttool with may be used both for tube straightening and for tube bending.

A further object of the invention is'to provide'such a tool in which certain of thetube straightening elements cooperate with certain added elements when the tool is used for tube bending.

Yet another object is to provide such a tool in which the bending elements do not interfere with the tube straightening functions of the tool, and in fact are completely out of the way when the tool is being used as a tube straightener.

Other objects and advantages will be apparent from the following detailed description taken in connection with the accompanying drawings in which:

Fig. l is an end elevational view of a combined tube straightening and bending tool made in accordance with the present invention, the view in broken lines and the arrow showing how the tool is oscillated when it is being used to straighten a piece of tubing;

Fig. 2 is a section taken as indicated along the line 2-2 of Fig. 1;

Fig. 3 is a view similar to Fig. 2 showing the tool in use for bending a piece of tubing, and

Fig. 4 is a section taken as indicated along the line 4 4 of Fig. 3.

While I have shown and shall hereinafter describe one embodiment of the invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as dened in the appended claims.

Referring to the drawings in greater detail and referring rst to Figs. 1 and 4, the tool of this invention has a frame, indicated generally at 10, which is cornposed of a pair of parallel plates 11 and 12 which are retained in parallel spaced relationship by means of shouldered assembly members 13, 14 and 15 which are threaded at their ends to receive assembly nuts 16, 17 and 18, respectively. The assembly members 13, 14 and 15 serve as spindles for rollers 19, 20 and 21, respectively, which are journalled thereon and centered between the plates 11 and 12 by means of identical pairs of spacer members 22. The plates 11 and 12 are of a size to tit States Patent conveniently in the palm of the hand, and are'tapered at the end away from the rollers so they are'easily gripped. Inturned flanges 11a and 12a provide a smooth surface wherefthe flesh in the rcrotch of the thumb is stretched in gripping the tool.

The rollers 19, 20 and 21 are provided, respectively, with circumferential grooves 23,' 24 and 25. The assembly members 13, 14 and 15 are arranged at the apices of an isosceles triangle with its base along a line between the members 13 and 14, and its apex at 15, the triangle being of such dimensions that the adjacent margins of the rollers 19, 20 and 21 lie in a plane which is parallel to the base of the triangle.

When the tool is in use for tube straightening asV shown in Fig. 2, a piecey of tubing is introduced into the cylindrical space 26 dened'by lines drawn tangent to the circumferential roller grooves '23, 24 and 25 and parallel to the line forming'the baseofl the triangle, and the tool is moved manually along the tube to pass any bends, such as T1 and T2, in the tube through said space. The tool ordinarily is oscillated through an angle of about as it ispassed over any bend in the tubing as indicated in dotted lines in Fig. l; and several passes usually are made.

As best seen in Figs. 2 and 3 there are a pair of registering slots 27 which are formed in the frame plates 11 and 12 adjacent a margin thereof and parallel to the space 26. Rotatably mounted in said slots is a finger wheel 28 which, as seen in'Fig. l, extends through the slotsr so that it may be readily turned with the fingers. The iinger wheel 28 is provided with a threadedaperture into which is screwed a threaded stud 29 on the inner end of which is va tubeA gripping block 30 which has in' its forward face-a tube-receiving` groove 31. Rotation of the linger wheel 28 moves the tubegrippingblock 30 between an idle position, shown in Fig. 2, where it is clear of a piece of tubing in the space 26, to a tube gripping position, shown in Fig. 3, in which its forwardedges, which cornprise the outer margins of the groove 31, are close adjacent the margin of the roller 21. When the tube gripping block 30 is in the position shown in Fig. 3 a piece of tubing T is held firmly in place so that it may be bent around the grooved roller 19.

In order to accomplish the bending operation, the device includes a bending lever, indicated generally at 32, which is provided with a handle 33 and a bending block 34 which has a tube receiving groove 35. Flanking the bending block 34 is a pair of spaced hooks 36 which span the roller 19 and are provided with registering recesses 37 which partially encircle the spacers 22 on the spindle for said roller so that the bending lever may be pivoted about said spindle, and is detachable therefrom. The length of the hooks 36 is' such that the face of the bending block 34 flanking the groove 35 is substantially in contact with the margin of the roller 19.

When the device is in use for tube bending, as seen in Fig. 3, a straight piece of tubing is introduced into the space 26 between the rollers 19, 20 and 21, and the tool gripping block 30 is moved into gripping engagement with a piece of tubing. The hooks 36 on the bending lever 32 are thenl engaged with the spindle for the roller 19 with the bending block 34 positioned above the tubing T in the same plane with the groove 25 inthe upper roller 21. The tubing may then be bent to any desired angle by swinging the bending lever 32 downwardly, using the recesses 37 and the hooks 36 to pivot the arm around the spindle. The bending block 34, which has its forward surfaces substantially in contact with the margin of the roller 19, bends the tubing around said roller, which therefore serves as a bending die.

I claim:

l. A hand operated tube' straightening and bending tool comprising: a frame; three grooved rollers journalled on spindles in said frame, said spindles being disposed at the apices of an isosceles triangle of such dimensions that the adjacent margins of the rollers lie in ra plane parallel to the base of the triangle to provide a straight tube receiving space defined by the grooves in the rollers; a grooved tube gripping block which is movable between an idle position and' a position in which the and partially encircle the spindle of said roller whereby the bending lever is detachable from said spindle.

3. A hand operated tube straightening and bending tool, comprising: a pair oi plates secured together in parallel, spaced relationship to provide a frame, said plates having registering slots adjacent and parallel to one margin; three grooved rollers journalled on spindles in said frame, said spindles being disposed at the apices of an isosceles triangle of such dimensions that the adjacent margins of the rollers lie in a plane parallel to the base of the triangle to provide a straight tube receiving space defined by the grooves in the rollers, said space being parallel to the slots in the plates; a linger Wheel which has its periphery projecting through said Slots in the plates, said wheel having a threaded aperture; a threaded stud extending through said aperture; a grooved tool gripping block mounted on the inner end of said stud so that rotation of said linger wheel moves said block between an idle position and a position in which the outer margin of the groove therein contacts vided with a groove whichmay be aligned with that in v said roller at the apex of the triangle, said bending 1ever having a pair of spaced hooks which span a second roller and partially encircle the spindle of said second roller whereby the bending lever may be detachably secured in pivotal relationship to said second roller, the lengths of said hooks being such that the outer margins of the groove in the bending block are substantially in Contact with the margin of said second roller when the bending lever is' engaged with said spindle.

4. The device of claim 1 in which the frame is provided with a pair of registering slots and said tube grip ping block is mounted on a threaded -stud extending through a linger Wheel, said linger wheel having a periphery projecting through tle slots in the frame.

5. The device of claim 1 in which the frame comprises a pair of parallel plates which are proportioned and tapered to t the hand and having matching inturned ilanges along onemargin providing a smooth surface.

References Cited in the le of this patent UNITED STATES PATENTS Great Britain Jan. 5, 1910 

